Patent GB-443520-A (GB)
Title: Improvements in an automatic starting and stopping apparatus for a diesel engine
IPC: H02J9/08
Filed: 1935-01-21
Abstract: 443,520. Substituting sources in service. IGARASHI, T., 22, Nishinagahoriminamidori, 3-chome, Nishiku, Osaka, Japan. Jan. 21, 1935, No. 2008. [Class 38 (iv)] [See also Group XXVII] An apparatus for automatically starting and stopping a Diesel engine is applicable to an engine driving a stand-by electric generator, which is to be started by compressed air on the failure of a supply of electric current. The apparatus comprises a controller S, which is driven from an electric motor M through an electromagnetic clutch C and selectively opens the circuits which control the motor and the clutch, a valve-controlling shaft 58 mechanically connected with the controller S and controlling the compressed-air starting valves and the fuel pump, and switches Ga, Gb which change the electric connections when the engine reaches pre-determined speeds. The motor M is switched on automatically by a relay, for instance upon the failure of an electric current supply. As shown, the motor M drives the shaft 17 of the controller S through worm gearing 51, 56, Fig. 2, and the clutch C, the member 52 of which is mounted on a spindle 50 splined in the worm 51 and carrying the armature 54a of an electromagnet 53, the clutch being normally held out of engagement by a spring 55. The shaft 17 is connected by a universal joint or through an intermediate shaft to the shaft 58, Fig. 4, which carries a cam 60, for opening a valve 62 in a pipe 63 for supplying compressed air to the starting-valve chest 64 of the engine, and a cam 61 for opening a byepass valve 65 on the fuel pump 67. An arm 16, Fig. 1, on the shaft 17 of the controller moves over an insulating disc provided with contact segments 9-11, 13-15 and an insulating segment 12 ; contacts 16a, 16b on the arm are connected to each other and are adapted respectively to engage the segments 9-11 and 15, while an insulated contact 16c on the arm bridges the segments 13, 14 except in the position shown in Fig. 1. The arm 16 is connected through the coil 18 of a relay Lb to the bus-bar N of a D.C. source, and the segments 9-11, 13-15 are connected respectively to a contact 19 of a reversing switch R through the coil 47 of a relay Lc ; contacts 40, 44 of the switches Ga, Gb ; a contact 7b, through the coil 48 of a relay Ld ; a contact 20 of the switch R ; and a contact 8b. In normal circumstances, the arm 16 is in the position shown in Fig. 1, and a bell-crank 1 is held, for example by an electromagnet 5 in an electric supply main, in a position in which a contact segment 2 bridges contacts 7a, 7b. When the current in the electromagnet 5 fails, a spring 6 moves the bell-crank 1 to break contact at 2 and to cause a segment 3 to bridge contacts 8a, 8b in the circuit of the coil 18 of the relay Lb, which shifts the switch R into a position in which the following contacts are closed : 19, 27 ; 21, 28, 22 ; 23, 29 ; and 25, 30. Circuits are thus closed through the coil 47 of the relay Lc; which switches on the coil 53 for the clutch 52, and through the motor N, field F, and a supplementary circuit through the coil 18 of the relay Lb. The motor M drives the shaft 17 of the controller S until the contact 16a engages the segment 10, when the circuit of the relay Lc, is opened and the clutch 52 is disengaged and the motor M stops. In this position of the shaft 17 the starting- air valve 62, Fig. 4, is opened and the engine is started. When the engine attains a sufficient speed under compressed air a contact 39, actuated for instance by a governor, closes contacts 40, 41 whereby the relay Lc is again actuated to restart the motor, turning the shaft 17 until the contact 16a engages the segment 11 and opens the circuit of the relay Lc. At the same time, the fuel supply to the engine is started by the closing of the byepass valve 65, Fig. 4. When the engine speed is accelerated nearly to normal, a contact 42 closes contacts 43, 44 whereby the relay Lc is again actuated and the motor M turns the shaft 17 until the contact 16a is at the point 12 and the contact 16b leaves the segment 15, breaking the circuits of the relays, the motor M, and the clutch magnet 53. The engine is then running at normal speed and the reversing switch R is returned to its original position by a spring 32. When normal conditions in the electric mains are restored, current in the electromagnet 5 causes the bell-crank 1 to break contact at 3 and to close at 2 the circuit of the relay Ld, which closes the circuits of the motor M without operating the reversing switch R. The motor then runs in the reverse direction, turning the shaft 17 and arm 16 back to the position shown in Fig. 1, when the circuit of the relay Ld is opened and the engine is stopped by the opening of the fuel byepass valve 65, Fig. 4. An emergency switch E, which enables the relay Ld to be actuated to stop the engine independently of the position of the bell-crank 1 and reversing switch R, may be actuated by a governor when the engine speed exceeds normal. In modifications (1) the controller comprises contact cams adjustably mounted on the shaft 17 ; and (2) a handle is mounted on the shaft 58 to enable the engine to be started by hand, a clutch between the shaft 58 and the shaft 17 being disengaged for the purpose.